CRAIG Ferguson hasn’t changed too much since our last chat 30 years ago. The rolled-up sleeves reveal he’s been Beckhaming the upper body rather a lot (hippy suns, sons’ names, Celtic symbols, tributes to his late parents etc) but the healthy vegan diet looks to be working and his light tan is redolent of Ayrshire summer, time spent cycling with an eight-year-old. It’s all confirmation that the once leather-trousered comedian’s days of getting completely leathered (a friend once described him as “the alky’s alky”) are long gone.

Yet you wonder how much 25 years of Hollywood – and life – has changed the head of the man who became a chat show king, besides adding a few grey hairs. Has the boy from Cumbernauld become more aloof now that he’s a squillionaire, been besties with the likes of Robin Williams and Carrie Fisher and, according to Frankie Boyle, “sha**** Sharon Stone”?

Is he still blinded by ambition? Does he consider himself a success? Does he still scowl at Scotland, the way he once did through an upturned whisky glass? And does the Ringo electronic parking system in Glasgow really get him that excited?

Right now, Ferguson’s excited to be performing stand-up at the Edinburgh Fringe. It was at the Fringe when he was spotted by an American agent and lured to Hollywood. “I went over for a couple of weeks to see if there was any work,” he recalls, grinning. “Two weeks turned into 25 years.”

Before we talk about Tinseltown, does he have his head round being back in Scotland? “Yes, because I started coming back in 2011, when I got the place in Ayrshire. When my oldest boy [Milo, 18] went to college I put my toe in the water with work here. And then Ford [Kiernan] came up with the Still Game offer [to play Callum].”

Ferguson’s time in Los Angeles produced an array of achievements. He wrote and starred in three movies, appeared in sitcoms, he directed, wrote three books and proved his chops as a comedy actor and radio host. The ten-year stint on The Late Late Show saw him become became a household name across America.

But what did he learn in the process? “When I got to Los Angeles I initially thought I was successful just by being there,” he says, with a knowing smile. “But fortunately I had blown it early enough in my career to be able to recover.

“I see young performers, and I was like them once, who think their talent is unique and this talent will dispel all problems you have; that if you’re late or drunk or an a**hole then it won’t matter. But what I’ve discovered is that talent isn’t that rare. It’s like your driver’s licence. You’re going to need it, but you have to ask, ‘What else do you have? Will people want to work with you? Are you going to be a di**?’”

He adds: “I don’t think there is any mystery in showbiz. The ones who survive are human beings. The ones who are gone are the ones who believed they were a rare genius. You see, genius is not rare. And there are plenty of people who could do the job I did. I was on time, I had a work ethic, but I think it’s mostly luck.” He smiles: “Yet at the same time there are plenty of f***ing no-talent s***bags making a fortune.”

During his twenties, the Glasgow years, Ferguson made a name for himself as his comedy alter ego Bing Hitler. He landed TV pilots. He suffered the false dawns. Talent was never in question. The real worry was his apparent commitment to self-destruction via drink. In Christmas 1991, broke, drunk and in London, with a screaming hopelessness in his head, he decided to end it all. But an intervention by a barman, and a glass of sherry, prevented his early exit.

Ferguson got sober in the new year and worked hard. After being talent spotted at the Fringe, he took off to LA and set out to conquer. “It was hard. You can’t tell people you once filled the Pavilion as Bing Hitler.”

Yet Hollywood loved him, the cheeky, handsome Scot was fresh and inventive. And he rocketed up the pecking order, bringing his comedy experience to the interview process. But what about the effect of being paid $12million a year? (He’s said to be worth north of $30million.) Did that change his attitude to others, to the job?

“That was a challenge,” he admits. “My answer to that is: ‘Sometimes’. There was a point when I was in danger of believing that the amount of money I got paid for a job was commensurate to how valuable it was to me artistically. I was caught up in financial indulgence.” Houses? Cars? “Yeah, yeah. All of that. But now that’s not the case; I’ve got a house in Glasgow and a but’n’ben in Ayrshire.” And a home in Hollywood? “I do, but it’s on the market.” He adds: “No. I think conspicuous wealth is vulgar. It’s Trump and his gold taps. And I admit I went through a bit of that.”

Did money blunt the edge? “I suppose money changes the way you think about the work you want to do. I don’t want to not work. And my wife gives the impression I’m better not hanging around the house.”

But if you’ve got the money, Craig, will you get out of bed for £500 a week plus travelling for a theatre tour? “I would work in theatre. If I felt I could contribute to a play.”

Having money, he says, means having choices. “I worked in a Glasgow bar [the Chip] for two years, I took all sorts of shows. You see, poverty reduces choice. That’s why I’ve always envied those Eton types who can afford to say, ‘I don’t know if this is the right project for me’. The wages always told me if it was the right project. But at least now I can weigh things up.”

Ferguson’s success on The Late Late Show was predicated upon funning, flirting. How seductive was it to have the likes of Meghan Markle ask him to pinch her skin, or actresses saying if they weren’t married they’d be taking him home there and then?

“I flirted with actresses in the same way I flirted with Hugh Laurie,” he says in a not entirely convincing voice. “It was all pretend. It would be foolish to think that was real. Remember, there were 200 people in the audience. There were cameras and crew all around. If I had believed any of that life then that would have been crazy. But it wasn’t real.”

Disillusionment increased the more Ferguson played with fake reality. For the first few years he’d get the call sheet in the morning and be excited by the names. “But what happens very quickly is that you see the name and you go, ‘God, it’s him again’. It’s like that Mel Brooks-Cary Grant story. The first time Mel met him, he was so excited. ‘Wow. Cary Grant.’ And they became friends. And they’d call each other. Then a few months later Mel’s wife says, ‘It’s Cary Grant on the phone’. And Mel thinks, ‘God, Cary Grant again’.

Ferguson adds: “I remember having Little Richard on the show. Wow. I was so impressed. And then the Pistols were on and I was like a screaming fan girl. But the kids on the show were like, ‘Who are these foul guys?’ It puts it in perspective.”

And Sharon Stone? “I didn’t sh** her. It never happened,” he says, smiling. “We had dinner once. But I didn’t even winch her.”

When did he come to feel like an ageing footballer, realising the career couldn’t last? “I felt that after the first week,” he smiles. “I was amazed to get past the first month, six months, a year.” He thinks for a moment. “Let’s drop the footballer analogy. Let’s go to boxing. In the last few years my thinking became, ‘If I keep doing this I’m going to get hurt. It will do my head in because it takes so much time and physical energy.’

“You see, I’d go home pretty much shattered every day. I was happy I’d got the job, but seven years in I’d had enough. It makes you crazy. It elevates levels of selfishness and self-importance. If you are in a work environment where 120 people are focused on me being in a good mood, well, I can’t be in a good mood all the time. Some days you just can’t cut it. So I spoke to my wife about it and she said, ‘After this contract we’re done’.”

But the Hollywood experience was invaluable. “The great thing about The Late Late Show was it demystified Hollywood for me. I met everybody. You get to see it’s a workplace. It’s sometimes glamorous but I used to say to Scottish people when they’d come to visit, ‘Look, when the sun isn’t shining, this place is Airdrie.” He adds quickly, “No disrespect to Airdrie.”

Ferguson worked hard at being funny. You can see on YouTube how he grasps for the comedy, makes it happen in the moment. But doing that every day hurts. And he had already been beset by mental health issues. “I can’t deny the darkness swirls around,” he says softly. “But, and maybe this is naive of me, I think everybody feels it.” He pauses: “Well, maybe not everybody, but most of us feel despair at some time.”

And those who are intelligent, creative, looking for challenges, are prone to seeing cliff edges when they run out of ground?

“Yes. When I was a young man, and I probably had this conversation with you back then, I wanted to tell you how f***ing great I was, how awesome I was, how much I was going to do. But all that was coming from insecurity. And I’m different now in the sense that I don’t mind telling you how terrible I feel at times. At times, the dark thoughts roll in like the f***ing weather and you can’t work out why.”

He’s right to be honest. The alternative is horrific. “Yes, there’s the isolation that creates. You feel you’re the only person who’s going through this.”

Teenage life had been frustrating. He was close to his parents, his father a post office worker who became a manager and his mother a teacher, but they had an atypical working-class west of Scotland relationship whereby deep thoughts were shared as often as bowls of tofu.

“I don’t know if I analysed much at that time. I was a daft boy. But I do know I was aggressive and ambitious and I don’t think that’s a particularly comfortable way to be. And I was also aggressively into the bevvy, which keeps you numb from the disappointments along the way.” He offers a wry grin: “Or maybe it increased the number of disappointments because you are steaming all the time. I’d no idea how stupit I was.”

And exceptionally clever. Ferguson left school aged 16, in 1978. He once said this had to do with an argument with a teacher about existentialism? “It wasn’t quite the argument about existentialism that drove me out the door. It was frustration. I was unlucky in my time in education because I fell right into the crypto-Soviet comprehensive education leveller which tried to level everyone the same way. I was a troubled boy who really needed a bit of help.

“I’m not saying I was gifted, but I felt frustrated and I left. And at 16 in 1978 I was always angsty, I was full of punk rock and it had a profound effect on me.” He became a drummer in Peter Capaldi’s band, The Dreamboys. Ferguson then tried stand-up, and was successful. The BBC Scotland shows followed. He loved appearing alongside the late, great Gerard Kelly in The Odd Couple. Ferguson’s Partick Thistle shirt-wearing Oscar was terrific, except that in his opening scene he was supposed to be seated at a dining table. He wasn’t. He sat on top of the back of the chair, with feet where backside should be.

And it was worrying. Not that he should topple and fall off (although there was a chance) but that this was a young performer you sensed trying too hard to be noticed. (Neil Simon, had he been dead at the time, would have been spinning in his grave.)

Desperately seeking attention? You bet. Fear of failure? For sure. But it hadn’t been rationalised at the time. Perhaps it manifested itself in the drinking, and anger, about his life in Cumbernauld and in Scotland? He once said: “I hate my country for the way it holds people back.” Does he still feel that way?

“That statement was made by a different man,” he admits. “I used to carry a bit of bitterness about Cumbernauld. But it wasn’t that bad. My sister [writer Lynn] says, ‘After 30, it’s you’. She’s right. You can’t blame anyone. Life’s your own fault.” He laughs: “And I can’t be responsible for anything I may have once said because when you talk as much as I do you end up saying s*** you should never have said.”

Indeed Glasgow, and Scotland, are now tattooed into his psyche. “Whatever gratitude I lacked as a young man in Scotland, I’m lucky to have found it. All the success I have pretty much comes from the G12 area. I got jobs, met great artistic people at the Tron, I got to do plays written by clever Russian guys. What I’ve learned is that I’m from Cumbernauld – but all I had to do was take a bus for success to happen. I just thought I had to go to Hollywood.”

He grins: “Yet Hollywood took away the debate I had with myself about whether I was successful. I know now I have been successful in a couple of different things. But for a long time I couldn’t admit that to myself. It didn’t feel Glaswegian to say that. What I’ve come to realise is if I don’t admit I’ve succeeded then I didnae. I have to admit it – or it’s not real. This doesn’t make me a bad person. It just makes me a lucky man.”

He still loves America and believes the country will right itself once again, after the Right have been quelled, but won’t be drawn on Scottish nationalism. “It’s so divisive. It’s like how you felt at school, whether you were Celtic or Rangers. You’re aware the absolutes don’t welcome discussion.” So politically he’s Partick Thistle? “Yes!” he says, in emphatic voice.

Besides being able to acknowledge his own talent and embracing external factors such as luck, Ferguson puts happiness down to having two great sons and a [third] wife, art dealer Megan Wallace Cunningham, whom he adores. “We met at a party in New York and Megan’s grandfather was from Edinburgh.” He laughs: “She’s from Vermont, which is to all intents and purposes South Ayrshire. She’s more Scottish than the Scots. She’s Born Again. Just as I am with America.”

Megan, he says, came into his life at exactly right time, which is to say the wrong time. After his second divorce Ferguson was so skint he was using large jars of Germolene.

“I was just starting The Late Late Show when we met and I’d gone through a tough divorce. This idea of California-splitting-it-all-down-the-middle? Forget it! That’s a myth perpetuated by people who want more. After my divorce I was on my uppers. But Megan was great. What’s also great is she’s not drawn to showbusiness.”

He’s long dismissed this notion of people simply being drawn to fame and cash. He’s existentialist in believing we are what we do. “I remember in my twenties someone talking about my girlfriend and saying to me, ‘She’s only going out with you because of who you are.’ I said, ‘You’re f***ing right. I am who I am. That’s why anybody goes out with anybody.’”

That’s not to say his recent life has been spent in wonderland. He’s had to endure loss. His parents, the likes of friends such as Carrie Fisher, Robin Williams and Dennis Hopper. He still misses Kelly. How do you deal with it, Craig? “Sing louder,” he says in quiet voice. “I guess the notion was thrust on me, just before I was 30. I had to learn to live one day at a time to survive alcohol. But it became a philosophy.”

Ferguson has always been fun company. Now he’s even funnier. He’s far, far more content. And he really loves the Ringo parking system. But he can’t relax completely though. “No,” he grins. “Just this very day I was moaning about something and my dear wife said to me, ‘Just say it’s all right’. You see I have a restlessness. A discontent.”

A need to move forward. Which is why he’s writing another book (an imagined meeting between St Mungo and Merlin) and going back to the stand-up stage, to talk about his life and very funny times. And it will be funny, because he can now laugh at himself in a way he once couldn’t.

“You know one of the reasons I came very low in acting?” he says, unconsciously offering an example. “That dug in the movie Babe gave a fantastic performance. So if you ever think you are the greatest actor ever, just look at what that dog can do.”

He laughs, and the bold Ferguson returns. “But here’s the thing. I’ve never come across a dog that can do an hour and a half at Carnegie Hall. A laugh comes all the way up from his belly. “At least I’m better than most dogs at comedy.”

Hobo Fabulous is at the Edinburgh Playhouse on August 11. Tickets